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Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, and hydrogen, with the molecular formula H 2 SO 4. It is a colorless, odorless, and viscous liquid that is miscible with water. [7] Structure ...
In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are Lewis bases. Nucleophilic describes the affinity of a nucleophile to bond with positively charged ...
This definition was refined by Ronald Gillespie in 1971, as any acid with an H 0 value lower than that of 100% sulfuric acid (−11.93). [3] George A. Olah prepared the so-called " magic acid ", so named for its ability to attack hydrocarbons , by mixing antimony pentafluoride (SbF 5 ) and fluorosulfonic acid (FSO 3 H). [ 4 ]
Tosyl group (blue) with a generic "R" group attached Tosylate group with a generic "R" group attached. Note the extra oxygen, compared to plain tosyl. In organic chemistry, a toluenesulfonyl group (tosyl group, abbreviated Ts or Tos [nb 1]) is a univalent functional group with the chemical formula −SO 2 −C 6 H 4 −CH 3.
H is a measure of the basicity of the nucleophile relative to protons, as defined by the equation: = + where the pK a is that of the conjugate acid of the nucleophile and the constant 1.74 is the correction for the pK a of H 3 O +. E n is the term Edwards introduced to account for the polarizability of the nucleophile.
In the laboratory, triflic acid is useful in protonations because the conjugate base of triflic acid is nonnucleophilic. It is also used as an acidic titrant in nonaqueous acid-base titration because it behaves as a strong acid in many solvents (acetonitrile, acetic acid, etc.) where common mineral acids (such as HCl or H 2 SO 4) are only moderately strong.
A Lewis base is also a Brønsted–Lowry base, but a Lewis acid does not need to be a Brønsted–Lowry acid. The classification into hard and soft acids and bases ( HSAB theory ) followed in 1963. The strength of Lewis acid-base interactions, as measured by the standard enthalpy of formation of an adduct can be predicted by the Drago–Wayland ...
the base is a poor nucleophile. Bases with steric bulk, (such as in potassium tert-butoxide ), are often poor nucleophiles. For example, when a 3° haloalkane is reacts with an alkoxide, due to strong basic character of the alkoxide and unreactivity of 3° group towards S N 2, only alkene formation by E2 elimination is observed.